Tool lifting device



Dec. 18, 1934.

P, MGSHANE 1,985,049

TOOL LIFTING DEVICE Filed April 12, 1952 WITNESSES:

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INVENTOR ATTbRNEY Patented Dec. 18, 1934 more]: STATES PATENT OFFICE -1',9 s5,049 TOOL LIFTING Davies Phelan McShanc, Pittsburgh, Pa,ass'i-gnor to Westinghouse Electric & FManufacturing Company, acorporation of =Rennsylvania Application April 12,1932, Serial No.604,694

4 Claims.

ing devices for tool operating machines.

More

specifically, this invention relates to a tool-lifting :device formoving the tool :of a machine, 5 such as a planer, shaper, power saw,etc, from an operative to an inoperative position .for a part of thecycle of operation of the machine, and from an inoperative to anoperative ;.position 'during the remainder of the cycle of operation ofthe machine.

In the operation :of planets, it is frequently necessary to provide forshifting .or lifting the cutting tool at the end of every cutting stroketo prevent dragging the cuttingedges of the tool over the work .in thereverse direction, :as the work table makes a return stroke.

The toolmitting the tool holder and to return stroke.-

01 :to return to "the the :end of reach In order to perform thisoperation, 'thewusual practice heretofore adoptedha's been to providemanually or mechanically operable means by which the operator may shiftthe cutting tool at the end of the cutting stroke and return it to theworking position at the end of the return stroke of thework table. .In

$01118 02585, a SYS- tem of complicated mechanical elements,-;le vers,shafts, gears, etc.--inter-connected with some operating part of the'tool machine iisutilized to automatically shift the tool block and toolfrom the normal working position during the cutting stroke toaninoperative position .-during the return stroke.

In-order toeliminate this manual operation or complicated. automaticmechanical operation, provision is made, in the present invention, forutilizing a spring actuated tool block :and :an .electromagnetcooperating therewith zto perform the tool-shifting operation,

when Qnecessary.

While; in this disclosure of the invention, the control system is being:applied to aiplaner, it will bereadily apparent, as the description procoeds, that it may also be applied to cmachine tools of various typescharacteristics.

-One 'of the objects having similar rating" p the drawing,l.-shows-af-front view :of a tool bf thisginvention; g h fl 'block,162,;provided#withxanadjustable tool carstated, .is 'to provide .:atool-shifting (system ffor planers and the :like which shall be "simple:and

efficient in mperation and. ac

tacturedsandinstalledp onomicallyizmanu- (oi. eo- 'se) A more specificobject :of, the invention is to provide .rfnr automatically shifting thetool block and tool,- by the icooperative action of mechanical andelectro-magnetio means interconnected with the electrical control systemOf the machine :being controlled.

. A broader object .of this invention is to control the toolashiftingoperation of ,a tool by {electro-magnetic control means.

A ,furtheraobl'ect .of the ,invention is :to provide for operating the:tool :block carrying a tool by coacting mechanical and Lelectromagneticmeans controlled .-by :the operation of the reversing switches .01 (thereversing :motor driving .a tool machine.

.lIt is also an object :of the invention to control electromagnetictool-shifting devices by the operation of reversing switches.

.A-nother object of the invention is to control took-shifting :devices.by the operation of switches controlled by the counter-electromotiveforce on the ,motor during the reversing operation of a reciprocating:mac'hine. ,Other objects and advantages of this invention willbecome-evident from the following description, taken in conjunction withthe :accom- :oanying drawing, inwhich:

,Figure 1 is a view in front lelevationof a tool block and tool carriedthereby of .a :tool operating machine; i

. Figs. 2 and 3 are wiews inside elevation, part 11y fin section, of thetool rblockishown in Fig. 1, :showingthe operative :and inoperativepositions, respectively, for .the :tool block and tool carried thereon;

Fig. 4 is a view in side elevation of a planer showing one generalarrangement for 'the'shiftable too'l and 5 shows, diagrammatically, justso much of the electric control system of the planer 'for illustratingthe cooperative action of this .invention with such :control system.

For "a 'moredetailedand complete showing of the control system per se,but not forming a part of this invention, reference should .be had tothe patent application ofGeorge E. King et al., filedMayfi, 1930, SerialNo -450,102. j

lReferring more particularly ;to the figures ingrier,fioaioriadjustingthe :toolwat an angle to the .work by means orrsthe adjustingvsorews .51, A rpivota'lly amounted "tool holder 4'l iscarried by .thectooliacaam'ier and securely holds the tool 40 by meansof the adjustable screw mechanisms 52.

Fig. 2 shows more of the details of the tool holder and tool carrier,showing the tool in normal working position, whereas Fig. 3 is a viewsimilar to Fig. 2, except that the electromagnetic tool-shifting device38 does not have its coil 36 energized. The spring 39, shown inconjunction with the pivotallymounted tool holder, is, therefore, freeto move the tool holder and tool 40 to the position shown in Fig. 3.

The tool carrier 50, consisting of magnetic material, has the coil 36 ofthe electromagnet 38 mounted in an annular groove. The tool holder 41 isalso of magnetic material, and may, therefore, be utilized toeffectively and firmly hold the tool holder in the position shown inFig. 2, if and when the coil 36 is energized. However, when the coil 36is not energized, the tool holder and tool will be disposed in theposition shown in Fig. 3. To prevent the possibility of having the toolholder stickor firmly held in the position shown in Fig. 2 when the coil36 is not energized, a shim ofnon-magnetic material 53 is interposedbetween the tool carrier 50 and the tool holder 41. Thenon-magneticshim, therefore, actslike an air gap, thus preventing sticking of thetool holder when the coil is not energized Referring to Fig. 5, a motor166is shown, which is of special design, including shunt field windings74 and 75 connected in parallel-circuit relation, series stabilizingfield winding 86, and series dynamic-braking resistor 105. The controlpanel 167, shown in Fig. 4, carries the main-line contactor 10,directional switches 11 and 12, the control relay 9 and other controlequipment not part of this invention.

In Fig. 4, the motor 166 is shown associated with the control panel 167,the planer, including, among other elements, the table 169, platen 160,crossbar standard 161 and tool holder 162. On the crossbar standard 161,or any other convenient part or" the planer, are supported one or morependant-switch stations 7 from each of which complete control of themotors 166 and 166 may be had. The pendant-switch stations are mountedin the most accessible places for the attendant.

Below the planer platen 160 and at the side of the table 169 ispositioned a. limit switch 6 having projecting levers 144 and 145. Atthe side of the platen are positioned a pair of lugs 147 and 148 whichmay be adjusted longitudinally of the platen 160 within grooves of T-shape. The levers 144- and cooperate with lugs 147 and 148,respectively, to control the reciprocations of the platen in a mannerset forth more in detail in the application of George E. King et a1.above mentioned.

For the purpose of this invention, it is suflicient to know that thelevers 144 and 145 operate limit switches in the housing 6 which in turnsuccessively effect the operation of a control relay, one or the otherof a pair of directional control relays, depending on the direction oftravel of the platen, i. e., whether in the cut or return direction, andone or the other of directional contactors 11 and 12, depending upon thereversing operation that is to be effected.

When the directional control relay for the out direction is caused 'tooperate; as above broadly. outlined, contact members 58 are :closed.Closure of contact members 58 establishes a circuit from the positive.line conductor 1 through conductor 57, contact members 58, conductor60, actuating coil 61 of the directional contactor 11 and conductors 59and 62, to the negative line conductor 2. A coil 64 of the directionalcontactor 12 is connected in parallel circuit relation to the actuatingcoil 61 by a circuit extending through conductor 63, coil 64 andconductors 59 and 62 to the negative line conductor 2. Thev effect ofcoil 64 at this stage is merely to insure that contact members 83 of thedirectional contactor 12 are held in closed position.

An instant after the closure of contact members 58, the main linecontactor 10 is caused to operate, by means not part of this invention,closing the contact members 69 and opening the contact members 103.Closure of the contact members 69 establishes a circuit from thepositive line conductor 1 through contact members 69, conductors 70 and71, contact members '79 of contactor 11, conductor 80, armature 81,conductor 82, contact members 83 of contactor 12, conductors 84 and 85,series stabilizing field winding 86 of motor 166 and the startingresistor 37, to the negative line conductor 2. celerating or startingresistor 87 may be shunted in a suitable and well known manner byaccelerating switch 102.

It should be noted that the operation of the directional contactor 11,which effects the opera- 2- tion of the platen in the cut direction,causes the interlocked contact members 31 to close, thereby establishinga circuit for the actuating coil 32 of control relay 9 by a circuit fromthe positive conductor 1 through conductor 30, contact members 31 ofcontactor l1, actuating coil 32 of relay 9 and conductor 33 to thenegative conductor 2.

Operation of the control relay 9 establishes a circuit from the positiveconductor 1 through conductor 34, contact members 35 of relay 9,actuating coil- 36 'of the tool-shifting electromagnet 38, and conductor37 to the negative supply conductor 2. The electromagnet 38 cooperateswith the pivotally mounted tool holder 41 carrying the tool 40. Acompression spring 39 disposed between the base or support 162 and theholder 41 biases the tool to the position shown. When the coil 36 isenergized as just'explained, the tool is firmly held in an op erative orvertical position as shown in Figs. 1, 2 and 4.

At the end of the cut stroke, care must be taken that the coil 36 is notdeenergized before the out has been completed and the motor has comesubstantially to rest, or else the tool will move to the position shownin Figs. 3 and 5, thereby making an improper finishing cut.

When the platen has traveled substantially to the end of the cut stroke,lug 147 actuates lever 144. Bya sequence broadly indicated heretofore,contact members 58, and contact members 69 of line contactor 10 arecaused to open. Opening of contact members 58, however, does notimmediately cause the opening of contact members. 31 and 79.Deenergization of the line contactor 10 causes closing of contactmembers 103.

Themoving masses of the machine in the out direction drivethe motor 166.as a generator to supplyenergy to the energy-dissipating dynamicbrakingresistor 105. The dynamic-braking circuit may be traced from the lefthand or positive terminal of the motor through conductor 80, contactmembers 79 of contactor 11, conductors '71, '70 and. 101,contact'members 103 of The accontactor 10, dynamic-braking resistor 105,conductors 85 and 84, contact members 83 of contactor 12 and conductor82 to the right hand or negative terminal of the motor. I

A minor dynamic-braking circuit is also established which circuit may betraced from the left side of the armature 81, through conductor 80,resistor 91, the parallel circuit of actuating coil 61 and conductor 59,and conductor 63 and back contact coil 64 of the directional contactors11 and 12, respectively, conductor 62, negative line conductor 2,contact members 102 of the shunt for the accelerating resistor 87,series stabilizing field Winding 86, conductors 85 and 84, contactmembers 83 and conductor 82 to the right hand terminal or negativeterminal of the armature. From the circuit just traced, it is apparentthat coils 61 and 64 are subjected to a voltage of the same sign as theline voltage, and that the cut directional contactor 11 is thus held upwith contact members 79 closed, whereas the return directional contactor12 is held down with the back contact members 83 closed despite the factthat line voltage has been re-' moved.

The cut directional contactor 11, during the dynamic-braking period,therefore, remains in the up position holding the contact members 31closed. The electro-magnetic tool-shifting device, therefor, remainsenergized until the counter-electromotive of the motor is quite low, i.e., when the motor has come substantially to rest. The tool thus movesto the end of the cutting stroke, and beyond, and immediately thereafterwhen the return directional contactor 12 operates and the cutdirectional contactor 11 has been moved to the inoperative position, thespring 39 moves the holder 41 and tool 40 to the non-work engagingposition shown in Figs. 3 and 5.

When return directional contactor 12 has operated, contact members 131are closed and contact members 108 are closed, thereby connecting themotor to the supply conductors 1 and 2 for reverse operation.

The sequence of operation for the control units controlling the reverseoperation is very similar to the sequence of operation for the outdirection, i. e., contact members 125 are closed and the actuating coil12'? of the return directional contactor 12 and the back coil 129 of thecut directional contactor 11 are energized. At the end of the returnstroke, the motor is stopped by a dynamic braking effect, and after themotor has come to rest, the out directional contactor 11 is operated,and in consequence, the tool is firmly and positively held in thework-engaging position against the action of the spring 39 by theelectro-magnetic means 38.

The invention is not to be restricted to" the specific structuraldetails, arrangement of parts or circuit connections herein set forth,as various modifications thereof may be effected Without departing fromthe spirit and scope of this invention, and it is desired that only suchlimitations shall be imposed as are indicated in the appended claims. 1

I claim as my invention: 1. In a system of control for a tool, a machinehaving a reciprocating member for holding a work piece, a motor formoving said member, a

tool-holder means for biasing said tool-holder to w an inoperativeposition, electromagnetic means including a coil for moving saidtool-holder from said inoperative position to an operative position, acontrol relay adapted to energize said coil when caused to operate, anda cut-directional contactor for causing the motor to operate saidreciprocating member in such a direction that the tool may cut the Workpiece on the reciproeating member and also adapted to operate thecontrol relay to energize said coil for the electromagnetic means.

2. In a system of control for a tool, a machine having a reciprocatingmember, a motor for operating said member, a tool-holder, means forbiasing said tool-holder to an inoperative posi-- tion, electromagneticmeans including a coil for moving said tool-holder from the inoperativeposition to an operative position, a control relay adapted'to energizesaid coil, and a directional contactor for the motor adapted to energizesaid control relay.

3. A tool-shifting device, comprising a pivotally mounted tool-blockcarrying an operating tool, electromagnetic means including an operatingcoil for shifting the tool from an inoperative to an operative positionwhen said coil is energized, in combination with a tool operatingmachine including a reciprocating table, a motor for reciprocating thetable, a line contactor, a pair of directional contactors, means forcontrolling the actuation of said directional contactors by themovements of said table, means for dynamically braking and stopping themovement of the table at each end ofits movement, a control relayadapted to be energized by the operation of one of said directionalcontactors,

means for effecting the energization of said control relay only duringmovement of said table, and a circuit adapted to be closed by theoperation of said control relay to energize said operating coil for saidelectromagnetic means.

4. A tool-shifting device, comprising a pivotally mounted tool-blockcarrying an operating tool, electromagnetic means including an operatingcoil for shifting the tool from an inoperative to an operative positionwhen said coil is energized, in combination with a tool operating,machine including a reciprocating table for reciprocating relative tosaid tool-block and with a system of control for the tool operatingmachine and said electromagnetic means, said system of controlincluding, an electric motor, a pair of directional contactors adaptedto be responsive to the reciprocating movements of said table forcontrolling the direction of operation of said motor, and a controlrelay adapted to be energized by one of said directional contactors, andcontrol the energization of said operating coil. 7

PHELAN MoSHANE.

